bindings/python/sigrok/core/classes.py

   1 ##
   2 ## This file is part of the libsigrok project.
   3 ##
   4 ## Copyright (C) 2013 Martin Ling <martin-sigrok@earth.li>
   5 ##
   6 ## This program is free software: you can redistribute it and/or modify
   7 ## it under the terms of the GNU General Public License as published by
   8 ## the Free Software Foundation, either version 3 of the License, or
   9 ## (at your option) any later version.
  10 ##
  11 ## This program is distributed in the hope that it will be useful,
  12 ## but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 ## GNU General Public License for more details.
  15 ##
  16 ## You should have received a copy of the GNU General Public License
  17 ## along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 ##
  19
  20 from functools import partial
  21 from fractions import Fraction
  22 from .lowlevel import *
  23 from . import lowlevel
  24 import itertools
  25
  26 __all__ = ['Error', 'Context', 'Driver', 'Device', 'Session', 'Packet', 'Log',
  27     'LogLevel', 'PacketType', 'Quantity', 'Unit', 'QuantityFlag', 'ConfigKey']
  28
  29 class Error(Exception):
  30
  31     def __str__(self):
  32         return sr_strerror(self.args[0])
  33
  34 def check(result):
  35     if result != SR_OK:
  36         raise Error(result)
  37
  38 def gvariant_to_python(value):
  39     type_string = g_variant_get_type_string(value)
  40     if type_string == 't':
  41         return g_variant_get_uint64(value)
  42     if type_string == 'b':
  43         return g_variant_get_bool(value)
  44     if type_string == 'd':
  45         return g_variant_get_double(value)
  46     if type_string == 's':
  47         return g_variant_get_string(value, None)
  48     if type_string == '(tt)':
  49         return Fraction(
  50             g_variant_get_uint64(g_variant_get_child_value(value, 0)),
  51             g_variant_get_uint64(g_variant_get_child_value(value, 1)))
  52     raise NotImplementedError(
  53         "Can't convert GVariant type '%s' to a Python type." % type_string)
  54
  55 def python_to_gvariant(value):
  56     if isinstance(value, int):
  57         return g_variant_new_uint64(value)
  58     if isinstance(value, bool):
  59         return g_variant_new_boolean(value)
  60     if isinstance(value, float):
  61         return g_variant_new_double(value)
  62     if isinstance(value, str):
  63         return g_variant_new_string(value)
  64     if isinstance(value, Fraction):
  65         array = new_gvariant_ptr_array(2)
  66         gvariant_ptr_array_setitem(array, 0,
  67             g_variant_new_uint64(value.numerator))
  68         gvariant_ptr_array_setitem(array, 1,
  69             g_variant_new_uint64(value.denominator))
  70         result = g_variant_new_tuple(array, 2)
  71         delete_gvariant_ptr_array(array)
  72         return result
  73     raise NotImplementedError(
  74         "Can't convert Python '%s' to a GVariant." % type(value))
  75
  76 def callback_wrapper(session, callback, device_ptr, packet_ptr):
  77     device = session.context._devices[int(device_ptr.this)]
  78     packet = Packet(session, packet_ptr)
  79     callback(device, packet)
  80
  81 class Context(object):
  82
  83     def __init__(self):
  84         context_ptr_ptr = new_sr_context_ptr_ptr()
  85         check(sr_init(context_ptr_ptr))
  86         self.struct = sr_context_ptr_ptr_value(context_ptr_ptr)
  87         self._drivers = None
  88         self._devices = {}
  89         self.session = None
  90
  91     def __del__(self):
  92         sr_exit(self.struct)
  93
  94     @property
  95     def drivers(self):
  96         if not self._drivers:
  97             self._drivers = {}
  98             driver_list = sr_driver_list()
  99             for i in itertools.count():
 100                 driver_ptr = sr_dev_driver_ptr_array_getitem(driver_list, i)
 101                 if driver_ptr:
 102                     self._drivers[driver_ptr.name] = Driver(self, driver_ptr)
 103                 else:
 104                     break
 105         return self._drivers
 106
 107 class Driver(object):
 108
 109     def __init__(self, context, struct):
 110         self.context = context
 111         self.struct = struct
 112         self._initialized = False
 113
 114     @property
 115     def name(self):
 116         return self.struct.name
 117
 118     def scan(self):
 119         if not self._initialized:
 120             check(sr_driver_init(self.context.struct, self.struct))
 121             self._initialized = True
 122         device_list = sr_driver_scan(self.struct, None)
 123         devices = [Device(self, gpointer_to_sr_dev_inst_ptr(ptr))
 124             for ptr in gslist_to_python(device_list)]
 125         g_slist_free(device_list)
 126         return devices
 127
 128 class Device(object):
 129
 130     def __new__(cls, driver, struct):
 131         address = int(struct.this)
 132         if address not in driver.context._devices:
 133             device = super(Device, cls).__new__(cls, driver, struct)
 134             driver.context._devices[address] = device
 135         return driver.context._devices[address]
 136
 137     def __init__(self, driver, struct):
 138         self.driver = driver
 139         self.struct = struct
 140
 141     def __getattr__(self, name):
 142         key = getattr(ConfigKey, name.upper())
 143         data = new_gvariant_ptr_ptr()
 144         try:
 145             check(sr_config_get(self.driver.struct,
 146                 key.id, data, self.struct))
 147         except Error as error:
 148             if error.errno == SR_ERR_NA:
 149                 raise NotImplementedError(
 150                     "Device does not implement %s" % name)
 151             else:
 152                 raise AttributeError
 153         value = gvariant_ptr_ptr_value(data)
 154         return gvariant_to_python(value)
 155
 156     def __setattr__(self, name, value):
 157         try:
 158             key = getattr(ConfigKey, name.upper())
 159         except AttributeError:
 160             super(Device, self).__setattr__(name, value)
 161             return
 162         check(sr_config_set(self.struct,
 163             key.id, python_to_gvariant(value)))
 164
 165     @property
 166     def vendor(self):
 167         return self.struct.vendor
 168
 169     @property
 170     def model(self):
 171         return self.struct.model
 172
 173     @property
 174     def version(self):
 175         return self.struct.version
 176
 177 class Session(object):
 178
 179     def __init__(self, context):
 180         assert context.session is None
 181         self.context = context
 182         self.struct = sr_session_new()
 183         context.session = self
 184
 185     def __del__(self):
 186         check(sr_session_destroy())
 187
 188     def add_device(self, device):
 189         check(sr_session_dev_add(device.struct))
 190
 191     def add_callback(self, callback):
 192         wrapper = partial(callback_wrapper, self, callback)
 193         check(sr_session_datafeed_python_callback_add(wrapper))
 194
 195     def start(self):
 196         check(sr_session_start())
 197
 198     def run(self):
 199         check(sr_session_run())
 200
 201     def stop(self):
 202         check(sr_session_stop())
 203
 204 class Packet(object):
 205
 206     def __init__(self, session, struct):
 207         self.session = session
 208         self.struct = struct
 209         self._payload = None
 210
 211     @property
 212     def type(self):
 213         return PacketType(self.struct.type)
 214
 215     @property
 216     def payload(self):
 217         if self._payload is None:
 218             pointer = self.struct.payload
 219             if self.type == PacketType.LOGIC:
 220                 self._payload = Logic(self,
 221                     void_ptr_to_sr_datafeed_logic_ptr(pointer))
 222             elif self.type == PacketType.ANALOG:
 223                 self._payload = Analog(self,
 224                     void_ptr_to_sr_datafeed_analog_ptr(pointer))
 225             else:
 226                 raise NotImplementedError(
 227                     "No Python mapping for packet type %ѕ" % self.struct.type)
 228         return self._payload
 229
 230 class Logic(object):
 231
 232     def __init__(self, packet, struct):
 233         self.packet = packet
 234         self.struct = struct
 235         self._data = None
 236
 237     @property
 238     def data(self):
 239         if self._data is None:
 240             self._data = cdata(self.struct.data, self.struct.length)
 241         return self._data
 242
 243 class Analog(object):
 244
 245     def __init__(self, packet, struct):
 246         self.packet = packet
 247         self.struct = struct
 248         self._data = None
 249
 250     @property
 251     def num_samples(self):
 252         return self.struct.num_samples
 253
 254     @property
 255     def mq(self):
 256         return Quantity(self.struct.mq)
 257
 258     @property
 259     def unit(self):
 260         return Unit(self.struct.unit)
 261
 262     @property
 263     def mqflags(self):
 264         return QuantityFlag.set_from_mask(self.struct.mqflags)
 265
 266     @property
 267     def data(self):
 268         if self._data is None:
 269             self._data = float_array.frompointer(self.struct.data)
 270         return self._data
 271
 272 class Log(object):
 273
 274     @property
 275     def level(self):
 276         return LogLevel(sr_log_loglevel_get())
 277
 278     @level.setter
 279     def level(self, l):
 280         check(sr_log_loglevel_set(l.id))
 281
 282     @property
 283     def domain(self):
 284         return sr_log_logdomain_get()
 285
 286     @domain.setter
 287     def domain(self, d):
 288         check(sr_log_logdomain_set(d))
 289
 290 class EnumValue(object):
 291
 292     _enum_values = {}
 293
 294     def __new__(cls, id):
 295         if cls not in cls._enum_values:
 296             cls._enum_values[cls] = {}
 297         if id not in cls._enum_values[cls]:
 298             value = super(EnumValue, cls).__new__(cls)
 299             value.id = id
 300             cls._enum_values[cls][id] = value
 301         return cls._enum_values[cls][id]
 302
 303 class LogLevel(EnumValue):
 304     pass
 305
 306 class PacketType(EnumValue):
 307     pass
 308
 309 class Quantity(EnumValue):
 310     pass
 311
 312 class Unit(EnumValue):
 313     pass
 314
 315 class QuantityFlag(EnumValue):
 316
 317     @classmethod
 318     def set_from_mask(cls, mask):
 319         result = set()
 320         while mask:
 321             new_mask = mask & (mask - 1)
 322             result.add(cls(mask ^ new_mask))
 323             mask = new_mask
 324         return result
 325
 326 class ConfigKey(EnumValue):
 327     pass
 328
 329 for symbol_name in dir(lowlevel):
 330     for prefix, cls in [
 331         ('SR_LOG_', LogLevel),
 332         ('SR_DF_', PacketType),
 333         ('SR_MQ_', Quantity),
 334         ('SR_UNIT_', Unit),
 335         ('SR_MQFLAG_', QuantityFlag),
 336         ('SR_CONF_', ConfigKey)]:
 337         if symbol_name.startswith(prefix):
 338             name = symbol_name[len(prefix):]
 339             value = getattr(lowlevel, symbol_name)
 340             setattr(cls, name, cls(value))